In this new R01 application, studies are proposed to develop a photostimulable storage phosphors (PSP) based method for alveolar bone mass quantification. The objective is to provide a method for using images from routine dental examinations to obtain bone mass measurements for osteoporotic risk assessment, treatment, monitoring, and research. The goal is to overcome previous problems of variations in X-ray intensity, unknown soft-tissue thickness, scatter radiation, and the non-linear response of film to radiation associated with conventional radiography. Four specific aims are proposed to address this goal. Aim 1 proposes studies to create a model to assess major sources of variation inherent in alveolar bone mass determinations by examining instrumental and subject variances (saliva, soft tissue etc.) by using spiral CT modeling of previous head scans (n=120) and CT - 3D imaging of phantoms with simulations. Aim 2 is to develop and evaluate an oral PSP appliance to quantitate alveolar bone mass. Studies are proposed to improve on their Intensity X-Ray Absorptiometry (IRXA) PSP model and attempt to perform QDER using two wavelengths (50 and 80 kvP). The target standards will be processed bone powder pellets assessed by the NIST. Aim 3 is to assess the accuracy of the PSP model in vivo utilizing single radiographic examinations. The investigators will work with stripped cadaveric jaws and cadaveric heads with a bone apatite block to assess accuracy and precision. Aim 4 proposes to establish the lower detection limit for alveolar bone mass change with PSP radiography by performing in vivo testing on 40 recall subjects at the SIU Dental School. The dentist will insert a 0.1 mm apatite sheet or tissue sheet in a blinded fashion to cover the alveolar section of interest and then examine initial and recall X-rays to define differences between conventional and PSP exposures. In addition the investigators will determine whether PSP radiography or dental films can detect change in bone mass by using the apatite sheet in vivo. They propose to create a model of major sources of measurement variation in quantitative dental radiography, develop and evaluate PSP methods for quantifying alveolar bone mass, and to determine the accuracy of the PSP methods for measuring bone mass. It is anticipated that these PSP methods will result in better prevention, diagnosis and treatment of bone loss and will facilitate research aimed at establishing risk factors for alveolar bone loss.